feat: fastmcpp 3.x parity sync

CMakeLists.txt

@@ -14,8 +14,6 @@ option(FASTMCPP_BUILD_EXAMPLES "Build examples" ON)
 option(FASTMCPP_ENABLE_POST_STREAMING "Enable POST streaming via libcurl (optional)" OFF)
 option(FASTMCPP_FETCH_CURL "Fetch and build libcurl statically for POST streaming" ON)
 option(FASTMCPP_ENABLE_SAMPLING_HTTP_HANDLERS "Enable built-in OpenAI/Anthropic sampling handlers (requires libcurl)" OFF)
-option(FASTMCPP_ENABLE_WS_STREAMING_TESTS "Enable WebSocket streaming tests (requires external server)" OFF)
-option(FASTMCPP_ENABLE_LOCAL_WS_TEST "Enable local WebSocket server test (depends on httplib ws server support)" OFF)
 
 add_library(fastmcpp_core STATIC
     src/types.cpp
@@ -24,7 +22,12 @@ add_library(fastmcpp_core STATIC
     src/providers/transforms/namespace.cpp
     src/providers/transforms/tool_transform.cpp
     src/providers/transforms/visibility.cpp
+    src/providers/transforms/version_filter.cpp
+    src/providers/transforms/prompts_as_tools.cpp
+    src/providers/transforms/resources_as_tools.cpp
     src/providers/filesystem_provider.cpp
+    src/providers/skills_provider.cpp
+    src/providers/openapi_provider.cpp
     src/proxy.cpp
     src/mcp/handler.cpp
     src/mcp/tasks.cpp
@@ -40,6 +43,8 @@ add_library(fastmcpp_core STATIC
     src/server/context.cpp
     src/server/middleware.cpp
     src/server/security_middleware.cpp
+    src/server/response_limiting_middleware.cpp
+    src/server/ping_middleware.cpp
     src/server/sampling.cpp
     src/server/http_server.cpp
     src/server/stdio_server.cpp
@@ -92,19 +97,6 @@ if(NOT cpp_httplib_POPULATED)
 endif()
 target_include_directories(fastmcpp_core PUBLIC ${cpp_httplib_SOURCE_DIR})
 
-# Header-only WebSocket client (easywsclient)
-FetchContent_Declare(
-  easywsclient
-  GIT_REPOSITORY https://github.com/dhbaird/easywsclient.git
-  GIT_TAG master
-)
-FetchContent_GetProperties(easywsclient)
-if(NOT easywsclient_POPULATED)
-  FetchContent_Populate(easywsclient)
-endif()
-target_include_directories(fastmcpp_core PUBLIC ${easywsclient_SOURCE_DIR})
-target_sources(fastmcpp_core PRIVATE ${easywsclient_SOURCE_DIR}/easywsclient.cpp)
-
 # Optional: libcurl for POST streaming and sampling handlers (modular)
 if(FASTMCPP_ENABLE_POST_STREAMING OR FASTMCPP_ENABLE_SAMPLING_HTTP_HANDLERS)
   if(FASTMCPP_FETCH_CURL)
@@ -248,6 +240,9 @@ if(FASTMCPP_BUILD_TESTS)
   add_test(NAME fastmcpp_cli_tasks_demo COMMAND fastmcpp tasks demo)
   add_executable(fastmcpp_cli_tasks_ux tests/cli/tasks_cli.cpp)
   add_test(NAME fastmcpp_cli_tasks_ux COMMAND fastmcpp_cli_tasks_ux)
+  add_executable(fastmcpp_cli_generated_e2e tests/cli/generated_cli_e2e.cpp)
+  target_link_libraries(fastmcpp_cli_generated_e2e PRIVATE fastmcpp_core)
+  add_test(NAME fastmcpp_cli_generated_e2e COMMAND fastmcpp_cli_generated_e2e)
 
   add_executable(fastmcpp_http_integration tests/server/http_integration.cpp)   
   target_link_libraries(fastmcpp_http_integration PRIVATE fastmcpp_core)        
@@ -273,6 +268,10 @@ if(FASTMCPP_BUILD_TESTS)
   target_link_libraries(fastmcpp_schema_build PRIVATE fastmcpp_core)
   add_test(NAME fastmcpp_schema_build COMMAND fastmcpp_schema_build)
 
+  add_executable(fastmcpp_schema_dereference_toggle tests/schema/dereference_toggle.cpp)
+  target_link_libraries(fastmcpp_schema_dereference_toggle PRIVATE fastmcpp_core)
+  add_test(NAME fastmcpp_schema_dereference_toggle COMMAND fastmcpp_schema_dereference_toggle)
+
   add_executable(fastmcpp_content tests/content.cpp)
   target_link_libraries(fastmcpp_content PRIVATE fastmcpp_core)
   add_test(NAME fastmcpp_content COMMAND fastmcpp_content)
@@ -477,6 +476,11 @@ if(FASTMCPP_BUILD_TESTS)
   target_link_libraries(fastmcpp_app_ergonomics PRIVATE fastmcpp_core)
   add_test(NAME fastmcpp_app_ergonomics COMMAND fastmcpp_app_ergonomics)
 
+  # MCP Apps metadata parity tests
+  add_executable(fastmcpp_app_mcp_apps tests/app/mcp_apps.cpp)
+  target_link_libraries(fastmcpp_app_mcp_apps PRIVATE fastmcpp_core)
+  add_test(NAME fastmcpp_app_mcp_apps COMMAND fastmcpp_app_mcp_apps)
+
   # Filesystem provider tests
   add_library(fastmcpp_fs_test_plugin SHARED tests/fs/test_plugin.cpp)
   target_compile_definitions(fastmcpp_fs_test_plugin PRIVATE FASTMCPP_PROVIDER_EXPORTS)
@@ -497,6 +501,18 @@ if(FASTMCPP_BUILD_TESTS)
   target_link_libraries(fastmcpp_provider_transforms PRIVATE fastmcpp_core)
   add_test(NAME fastmcpp_provider_transforms COMMAND fastmcpp_provider_transforms)
 
+  add_executable(fastmcpp_provider_version_filter tests/providers/version_filter.cpp)
+  target_link_libraries(fastmcpp_provider_version_filter PRIVATE fastmcpp_core)
+  add_test(NAME fastmcpp_provider_version_filter COMMAND fastmcpp_provider_version_filter)
+
+  add_executable(fastmcpp_provider_skills tests/providers/skills_provider.cpp)
+  target_link_libraries(fastmcpp_provider_skills PRIVATE fastmcpp_core)
+  add_test(NAME fastmcpp_provider_skills COMMAND fastmcpp_provider_skills)
+
+  add_executable(fastmcpp_provider_openapi tests/providers/openapi_provider.cpp)
+  target_link_libraries(fastmcpp_provider_openapi PRIVATE fastmcpp_core)
+  add_test(NAME fastmcpp_provider_openapi COMMAND fastmcpp_provider_openapi)
+
   # Proxy tests
   add_executable(fastmcpp_proxy_basic tests/proxy/basic.cpp)
   target_link_libraries(fastmcpp_proxy_basic PRIVATE fastmcpp_core)
@@ -507,6 +523,31 @@ if(FASTMCPP_BUILD_TESTS)
   target_link_libraries(fastmcpp_main_header PRIVATE fastmcpp_core)
   add_test(NAME fastmcpp_main_header COMMAND fastmcpp_main_header)
 
+  # Sync-cycle tests (Phase 11)
+  add_executable(fastmcpp_mcp_error_codes tests/mcp/test_error_codes.cpp)
+  target_link_libraries(fastmcpp_mcp_error_codes PRIVATE fastmcpp_core)
+  add_test(NAME fastmcpp_mcp_error_codes COMMAND fastmcpp_mcp_error_codes)
+
+  add_executable(fastmcpp_pagination tests/mcp/test_pagination.cpp)
+  target_link_libraries(fastmcpp_pagination PRIVATE fastmcpp_core)
+  add_test(NAME fastmcpp_pagination COMMAND fastmcpp_pagination)
+
+  add_executable(fastmcpp_tools_transform_enabled tests/tools/test_tool_transform_enabled.cpp)
+  target_link_libraries(fastmcpp_tools_transform_enabled PRIVATE fastmcpp_core)
+  add_test(NAME fastmcpp_tools_transform_enabled COMMAND fastmcpp_tools_transform_enabled)
+
+  add_executable(fastmcpp_tools_sequential tests/tools/test_tool_sequential.cpp)
+  target_link_libraries(fastmcpp_tools_sequential PRIVATE fastmcpp_core)
+  add_test(NAME fastmcpp_tools_sequential COMMAND fastmcpp_tools_sequential)
+
+  add_executable(fastmcpp_session_state tests/server/test_session_state.cpp)
+  target_link_libraries(fastmcpp_session_state PRIVATE fastmcpp_core)
+  add_test(NAME fastmcpp_session_state COMMAND fastmcpp_session_state)
+
+  add_executable(fastmcpp_response_limiting tests/server/test_response_limiting.cpp)
+  target_link_libraries(fastmcpp_response_limiting PRIVATE fastmcpp_core)
+  add_test(NAME fastmcpp_response_limiting COMMAND fastmcpp_response_limiting)
+
   set_tests_properties(fastmcpp_stdio_client PROPERTIES
     LABELS "conformance"
     WORKING_DIRECTORY "$<TARGET_FILE_DIR:fastmcpp_stdio_client>"
@@ -527,20 +568,6 @@ if(FASTMCPP_BUILD_TESTS)
     set_tests_properties(fastmcpp_streaming_sse PROPERTIES RUN_SERIAL TRUE)
   endif()
 
-  if(FASTMCPP_ENABLE_WS_STREAMING_TESTS)
-    add_executable(fastmcpp_ws_streaming tests/transports/ws_streaming.cpp)     
-    target_link_libraries(fastmcpp_ws_streaming PRIVATE fastmcpp_core)
-    add_test(NAME fastmcpp_ws_streaming COMMAND fastmcpp_ws_streaming)
-    # Test auto-skips if FASTMCPP_WS_URL is not set
-
-    if(FASTMCPP_ENABLE_LOCAL_WS_TEST)
-      add_executable(fastmcpp_ws_streaming_local tests/transports/ws_streaming_local.cpp)
-      target_link_libraries(fastmcpp_ws_streaming_local PRIVATE fastmcpp_core)  
-      add_test(NAME fastmcpp_ws_streaming_local COMMAND fastmcpp_ws_streaming_local)
-      set_tests_properties(fastmcpp_ws_streaming_local PROPERTIES RUN_SERIAL TRUE)
-    endif()
-  endif()
-
   # POST streaming transport test (requires libcurl)
   if(FASTMCPP_ENABLE_POST_STREAMING AND TARGET CURL::libcurl)
     add_executable(fastmcpp_post_streaming tests/transports/post_streaming.cpp)
@@ -585,6 +612,18 @@ if(FASTMCPP_BUILD_EXAMPLES)
   add_executable(fastmcpp_example_tags_example examples/tags_example.cpp)
   target_link_libraries(fastmcpp_example_tags_example PRIVATE fastmcpp_core)
 
+  # MCP Apps example (FastMCP 3.x surface)
+  add_executable(fastmcpp_example_mcp_apps examples/mcp_apps.cpp)
+  target_link_libraries(fastmcpp_example_mcp_apps PRIVATE fastmcpp_core)
+
+  # Skills provider example
+  add_executable(fastmcpp_example_skills_provider examples/skills_provider.cpp)
+  target_link_libraries(fastmcpp_example_skills_provider PRIVATE fastmcpp_core)
+
+  # OpenAPI provider example
+  add_executable(fastmcpp_example_openapi_provider examples/openapi_provider.cpp)
+  target_link_libraries(fastmcpp_example_openapi_provider PRIVATE fastmcpp_core)
+
   # Context API example (v2.13.0+)
   add_executable(fastmcpp_example_context_introspection examples/context_introspection.cpp)
   target_link_libraries(fastmcpp_example_context_introspection PRIVATE fastmcpp_core)
@@ -605,6 +644,10 @@ if(FASTMCPP_BUILD_EXAMPLES)
   add_executable(fastmcpp_example_tool_injection_middleware examples/tool_injection_middleware.cpp)
   target_link_libraries(fastmcpp_example_tool_injection_middleware PRIVATE fastmcpp_core)
 
+  # Response Limiting Middleware example
+  add_executable(fastmcpp_example_response_limiting_middleware examples/response_limiting_middleware.cpp)
+  target_link_libraries(fastmcpp_example_response_limiting_middleware PRIVATE fastmcpp_core)
+
   # Server Metadata example (v2.13.0+)
   add_executable(fastmcpp_example_server_metadata examples/server_metadata.cpp)
   target_link_libraries(fastmcpp_example_server_metadata PRIVATE fastmcpp_core)

README.md

@@ -11,7 +11,7 @@
 
 ---
 
-fastmcpp is a C++ port of the Python [fastmcp](https://github.com/jlowin/fastmcp) library, providing native performance for MCP servers and clients with support for tools, resources, prompts, and multiple transport layers (STDIO, HTTP/SSE, WebSocket).
+fastmcpp is a C++ port of the Python [fastmcp](https://github.com/jlowin/fastmcp) library, providing native performance for MCP servers and clients with support for tools, resources, prompts, and MCP-standard transport layers (STDIO, HTTP/SSE, Streamable HTTP).
 
 **Status:** Beta – core MCP features track the Python `fastmcp` reference.
 
@@ -20,7 +20,7 @@ fastmcpp is a C++ port of the Python [fastmcp](https://github.com/jlowin/fastmcp
 ## Features
 
 - Core MCP protocol implementation (JSON‑RPC).
-- Multiple transports: STDIO, HTTP (SSE), Streamable HTTP, WebSocket.
+- Multiple transports: STDIO, HTTP (SSE), Streamable HTTP.
 - Streamable HTTP transport (MCP spec 2025-03-26) with session management.
 - Tool management and invocation.
 - Resources and prompts support.
@@ -47,7 +47,6 @@ Optional:
 
 - libcurl (for HTTP POST streaming; can be fetched when `FASTMCPP_FETCH_CURL=ON`).
 - cpp‑httplib (HTTP server, fetched automatically).
-- easywsclient (WebSocket client, fetched automatically).
 
 ## Building
 
@@ -68,8 +67,7 @@ cmake -B build -S . \
   -DCMAKE_BUILD_TYPE=Release \
   -DFASTMCPP_ENABLE_POST_STREAMING=ON \
   -DFASTMCPP_FETCH_CURL=ON \
-  -DFASTMCPP_ENABLE_STREAMING_TESTS=ON \
-  -DFASTMCPP_ENABLE_WS_STREAMING_TESTS=ON
+  -DFASTMCPP_ENABLE_STREAMING_TESTS=ON
 ```
 
 Key options:
@@ -80,7 +78,6 @@ Key options:
 | `FASTMCPP_ENABLE_POST_STREAMING` | OFF     | Enable HTTP POST streaming (requires libcurl)   |
 | `FASTMCPP_FETCH_CURL`           | OFF     | Fetch and build curl (via FetchContent) if not found |
 | `FASTMCPP_ENABLE_STREAMING_TESTS` | OFF   | Enable SSE streaming tests                      |
-| `FASTMCPP_ENABLE_WS_STREAMING_TESTS` | OFF | Enable WebSocket streaming tests                |
 
 ### Platform notes
 
@@ -276,7 +273,6 @@ int main() {
 
 The `create_proxy()` factory function automatically detects the transport type from the URL:
 - `http://` or `https://` URLs use HTTP transport
-- `ws://` or `wss://` URLs use WebSocket transport
 
 Local tools, resources, and prompts take precedence over remote ones with the same name.
 

examples/mcp_apps.cpp

@@ -0,0 +1,62 @@
+#include "fastmcpp/app.hpp"
+#include "fastmcpp/mcp/handler.hpp"
+#include "fastmcpp/server/stdio_server.hpp"
+
+#include <string>
+
+int main()
+{
+    using fastmcpp::AppConfig;
+    using fastmcpp::FastMCP;
+    using fastmcpp::Json;
+
+    FastMCP app("mcp_apps_example", "1.0.0");
+
+    // Tool with MCP Apps metadata under _meta.ui (resourceUri + visibility)
+    FastMCP::ToolOptions tool_opts;
+    AppConfig tool_ui;
+    tool_ui.resource_uri = "ui://widgets/echo.html";
+    tool_ui.visibility = std::vector<std::string>{"tool_result"};
+    tool_opts.app = tool_ui;
+
+    app.tool("echo_ui", [](const Json& in) { return in; }, tool_opts);
+
+    // UI resource: mime_type defaults to text/html;profile=mcp-app for ui:// URIs
+    FastMCP::ResourceOptions resource_opts;
+    AppConfig resource_ui;
+    resource_ui.domain = "https://example.local";
+    resource_ui.prefers_border = true;
+    resource_opts.app = resource_ui;
+
+    app.resource(
+        "ui://widgets/home.html", "Home Widget",
+        [](const Json&)
+        {
+            return fastmcpp::resources::ResourceContent{
+                "ui://widgets/home.html", std::nullopt,
+                std::string{"<html><body><h1>Home</h1></body></html>"}};
+        },
+        resource_opts);
+
+    // UI resource template with per-template metadata
+    FastMCP::ResourceTemplateOptions templ_opts;
+    AppConfig templ_ui;
+    templ_ui.csp = Json{{"connectDomains", Json::array({"https://api.example.test"})}};
+    templ_opts.app = templ_ui;
+
+    app.resource_template(
+        "ui://widgets/{name}.html", "Named Widget",
+        [](const Json& params)
+        {
+            const std::string name = params.value("name", "unknown");
+            return fastmcpp::resources::ResourceContent{
+                "ui://widgets/" + name + ".html", std::nullopt,
+                std::string{"<html><body><h1>" + name + "</h1></body></html>"}};
+        },
+        Json::object(), templ_opts);
+
+    auto handler = fastmcpp::mcp::make_mcp_handler(app);
+    fastmcpp::server::StdioServerWrapper server(handler);
+    server.run();
+    return 0;
+}

examples/openapi_provider.cpp

@@ -0,0 +1,38 @@
+#include "fastmcpp/providers/openapi_provider.hpp"
+
+#include "fastmcpp/app.hpp"
+
+#include <iostream>
+#include <memory>
+
+int main()
+{
+    using namespace fastmcpp;
+
+    Json spec = Json::object();
+    spec["openapi"] = "3.0.3";
+    spec["info"] = Json{{"title", "Example API"}, {"version", "1.0.0"}};
+    spec["servers"] = Json::array({Json{{"url", "http://127.0.0.1:8080"}}});
+    spec["paths"] = Json::object();
+    spec["paths"]["/status"]["get"] = Json{
+        {"operationId", "getStatus"},
+        {"responses",
+         Json{{"200", Json{{"description", "ok"},
+                           {"content",
+                            Json{{"application/json",
+                                  Json{{"schema",
+                                        Json{{"type", "object"},
+                                             {"properties",
+                                              Json{{"status", Json{{"type", "string"}}}}}}}}}}}}}}},
+    };
+
+    FastMCP app("openapi-provider-example", "1.0.0");
+    auto provider = std::make_shared<providers::OpenAPIProvider>(spec);
+    app.add_provider(provider);
+
+    std::cout << "OpenAPI tools discovered:\n";
+    for (const auto& tool : app.list_all_tools_info())
+        std::cout << "  - " << tool.name << "\n";
+    std::cout << "Run a compatible HTTP server at http://127.0.0.1:8080 to invoke these tools.\n";
+    return 0;
+}

examples/response_limiting_middleware.cpp

@@ -0,0 +1,36 @@
+#include "fastmcpp/server/response_limiting_middleware.hpp"
+
+#include "fastmcpp/server/server.hpp"
+
+#include <iostream>
+#include <string>
+
+using namespace fastmcpp;
+
+int main()
+{
+    server::Server srv("response_limiting_demo", "1.0.0");
+
+    srv.route("tools/call",
+              [](const Json& payload)
+              {
+                  Json args = payload.value("arguments", Json::object());
+                  std::string text = args.value("text", std::string(120, 'A'));
+                  return Json{
+                      {"content", Json::array({{{"type", "text"}, {"text", text}}})},
+                  };
+              });
+
+    server::ResponseLimitingMiddleware limiter(48, "... [truncated]");
+    srv.add_after(limiter.make_hook());
+
+    Json req = {
+        {"name", "echo_large"},
+        {"arguments",
+         {{"text",
+           "This response is intentionally long so middleware truncation is easy to see."}}}};
+
+    auto resp = srv.handle("tools/call", req);
+    std::cout << resp.dump(2) << "\n";
+    return 0;
+}